


The Proof is in the Cave

by loofingaround



Category: Batman - All Media Types, Batman Beyond, DCU
Genre: Angst, Autistic Matt, Bruce Wayne is Trying, Gen, Hurt No Comfort, If You Squint - Freeform, Light Cussing From a Child, Not actually as bad as it sounds like its not that angsty theres just no fluff, Spliced Terry, a bit of describing a wound but not much, this canonically makes no sense, well i mean bruce tries but he sucks
Language: English
Status: Completed
Published: 2020-07-08
Updated: 2020-07-08
Packaged: 2021-03-05 00:07:24
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,999
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25155199
Author URL: https://archiveofourown.org/users/loofingaround/pseuds/loofingaround
Summary: Matt just wanted some light mischief, not a mind boggling trip down "My Brother is Batman" lane.
Comments: 7
Kudos: 46





	The Proof is in the Cave

Initially, the plan was to go straight home. But plans change, so Matt was still out on the streets of Gotham. Late at night. Alone. If his mom knew, she'd kill him, luckily his mom didn't know. She was at training for work and thought Matt was safe at home with Terry. Terry had left home in a rush though, claiming Mr. Wayne needed him immediately, so Matt was left to his own devices. It's a strange domino effect, but he's here now, looking for something fun to do before his mom gets home.

It'd be easier to have fun if he could just go to an arcade or stop by GameGo, but with only about 3 bucks and some change in his pocket, he wasn't getting anything. Matt wandered around a corner thinking over his predicament, considering just turning around and heading home, when a window broke across the street.

Matt looked both ways before taking off to the other side of the road, seeing a chair laying on the ground shrouded by glass. Inside the building from which the chair came, was Batman and some spliced kids fighting.

"Whoa, way schway," Matt muttered, scrambling for his phone to take a video. No way his friends would believe him if he told them how close he was to THE Batman!

There was yelling inside the building, but it was too muffled to make out, the commotion was on the opposite side of the room and Matt could barely seen anything. Blindly taking photos, Matt stepped back and read the address of the building. "This is the police commissioners quarters... What's she doing with Batman and these goons?" Matt moved to get a better look inside when suddenly a ram-ified man smashed through the remaining debris of the window. He hissed in pain, struggling to sit up as another man crashed through on top of him. Matt tripped backwards, scrambling to get away from them.

The Ram looked at him, hitting his friend and gesturing towards Matt, "grab em, maybe we can use him as a distraction." Matt turned, trying to stand and run when one of the men grabbed him. He didn't look to see which before breaking out into yelling, kicking at the man's legs and scratching at his arms.

"Fuck- let me go! When Batman finds out about this, he'll kick your butts!"

"Big language for such a little man," the snake-y man laughed, "it's not us you should be afraid of. We won't hurt you, but we will leave you for the Bat." 

Matt jerked his head back, smashing into the Snakes chin, not having noticed he was being dragged towards the building. It wasn't until his head was smashed against the wall did he realize how close he was to the broken window. His vision blacked for a second, spots swarming in front of his eyes. He went limp as he tried to process the pain, and then, like a doll, he was being tossed through the hole the other two men had created previously.

"C'mon, Red," Ram called to a girl, "let Batman finish them off!" 

Matt cringed from the ground, body throbbing in pain. "What losers, can't handle Batman and gotta run away," he mumbled, trying to sit up.

"Batman, you need to stop, what's happened to you?" The commissioner called out, crowded against the wall with her husband. 

"Whoa, holy shit- I mean shoot. What's wrong with him," Matt mumbled, shrinking away from the scene ahead.

Batman was clutching at his head, hissing at the commissioner. Frothing at the mouth and groaning in pain while making threatening swipes at the two, Matt couldn't believe it. 

Matt shifted backwards, trying to stay quiet, until he accidentally bumped into one of the broken tables, causing collapsing pieces of it to smash to the ground.

"My luck," Matt sucked in a breath of air, flinching when Batman jerked around. Staring him down, Batman seemed to fluctuate through a few emotions before deciding that killing Matt was the best answer.

Or at least that's what it seemed like to Matt as the other took off towards him, enlarged teeth bared. 

"Batman, stop!" The commissioner called, dashing towards them both as well. Matt freezed, hunching over himself and throwing his hands in front of his face in a weak attempt to protect himself. If Batman had sent those splicers running earlier and did all this damage, there was no way Matt was making this out unscathed.

It was strong, sleek arms wrapping around him that made him open his eyes back up. Rather than tackle him and rip his throat out, Batman was holding him? And crushing him against his chest in what almost felt like a too strong hug?

The commissioner slid to a halt, stopping a few feet in front of them as Batman hissed at her, gripping Matt against him. "Alright Batman, let the kid go. You're scaring him," she tried, speaking in a softer voice.

Batman pulled Matt away slightly, looking down at him and making upset whines. He rubbed at Matt's forehead, his fingers pressing into a fresh scrape and making Matt whine back. In the commotion, Matt hadn't realized at some point he'd garnered a cut, but Batman had jerked back and blood was staining the same fingers that had just inspected his earlier wounds.

"We can help him, you just have to hand him to me. Then we can help you," the commissioner took a step forward and Batman jerked him back. He growled at the elder lady, his fangs and mask coated in spittle, hoarding Matt back towards himself. Matt threw his arm out, reaching at the commissioner, hoping to end this here and go home and forget this ever happened.

She reached out, almost touching his hand when Matt suddenly lurched up, Batman readjusting him haphazardly as they shot up into the air. Matt hadn't flown before, at least not like this, and the rush of air around him was nauseating. He gripped onto Batman, grunting in more pain, trying to block out all the noise.

Not before too long it got quiet. Deafeningly quiet which was just as bad, in Matt's humble opinion. He gripped at his ears, smacking at the symbol on Batman's chest in an attempt to get him to let Matt down.

The sounds of ripping at Matt opening his eyes, squinting against the rush in his head at the darkness around them to see that Batman was changing. More bat-y features emerging and ripping through his suit. He looked to be in pain as well, trying to fight the change as he stumbled through the dark of what looked like a cave.

Matt flinched away, fear pushing him to kick at his hero, slamming his fists against the others chest. Meltdown forgotten, Matt focused on escape, he didn't want to be around when Batman went full bat shit crazy.

"Let me go! Get off of me!" Matt screamed, his voice echoing through the cave. 

Batman held tight, hissing at him and shaking him around a bit, moving forward still to what seemed to be light. Was this the Batcave? Matt shook his head, he could fanboy later, right now he was about to be squashed to death by an overgrown Batman. 

"Batman?" An older, stern voice echoed out as a figure appeared against the stark lights.

"Help! Batman's not okay! He's gonna kill me!" Matt yelled, ignoring the Bat's whine.

A dog came rushing at them, snarling and biting. Batman dropped him, pushing him away from the dog and taking lead, kicking at the animal.

Matt scurried away from the two, inching towards the other figure. He was grabbed by the ankle, pulled back towards Batman, when the man from before made his move.

The man slammed his shoulder into Batman, grunting in exertion. Batman let out a cry, more ripping fabric falling to the ground as bat ears and wings started to grow from the hero. After Batman released him, pushed back from the hit, Matt ducked down, covering his head with his arms. Eyes squeezed shut, he listened to the sounds of the two men fighting before it all went quiet.

Looking around for the two, Matt spotted the figure of Batman, now returned to a much more human state. Oddly, from a distance he looked familiar, and Matt couldn't help edging forward. 

The man from before, now clearly also quite older, was bent over, gasping for air. Matt shuffled over, sliding to halt beside the man.

"Whoa, are you okay? Is he okay?" Matt asked, trying to find if the man had any wounds.

"Pills," he choked out, "on the computer." 

Matt looked around, spotting a massive computer surrounded by several fancy gadgets and rows and old belongings. Getting up he ignored the pain radiating throughout his body and limped to the computer, ignoring the part of his mind that screamed at him that he was in the  _ Batcave _ standing across from a row of old  _ Batsuits _ .

He found the pills easily enough, not knowing the name on the label but recognising they must be important. Taking them back to the older man, he took the requested amount out of the bottle and handed them over. 

The man wore a mask, something strange and old looking that may have even come out of one of the costume cases surrounding them, Matt supposed, but to take the pills, he had to remove it.

Matt swore this felt like a moment off tv, like cameras would come out any moment and tell him it was all a joke. That a laugh track would start playing and he'd join in and it'd all be silly.

"Mr. Wayne?" Matt questioned, ignoring the man's glare and harsh breathing, "why are you... Is this not the Batcave?" Matt backed away, jerking towards the still figure of Batman. Too many thoughts pushed through his mind, making it hard to focus on anything, but Mr. Wayne's voice pushed through all the noise.

"Matthew, this is an accident. Batman brought you here by mistake, he wasn't sane in the mind." But that didn't make sense. Who just had a cave laying around, and how would Batman just so happen to fall in here? And how would Mr. Wayne just so happen to have a cure for whatever happened to Batman? And why did he have all of these old Batman belongings? And and and and-

Matt's vision was shot, black dots swimming in front of his eyes and confusing him further as he blocked out whatever other lies Mr. Wayne was trying to feed him. He crawled towards Batman, trying to ignore the pounding in his ears. The figure was mostly human again, his nails still a little too long and his ears a bit pointed, but human.

"Terry?"

The resemblance was impossible to deny. Up close, leaning over Batman and staring him in the face, it was obvious. His brother-  _ Matt's brother _ was laying out in front of him, roughed up from battle, in the Batsuit. Matt fiddled with the ripped bits of suit on his chest, stretching out the bit of fabric that held the bat symbol. It felt like things were moving too slow, that his fingers weren't working right, that his breathing was wrong. That Terry's breathing was wrong. Was Terry even breathing?

A hand on his shoulder jump started his mind, and he shoved his arms out in defense as he was pulled back. Mr. Wayne was holding him and telling him something though, and Matt stopped flinging his limbs about, not wanting to hurt him. He couldn't tell what Mr. Wayne was saying, but he fell back into the weak embrace. 

After some moments of feeling the words Mr. Wayne spoke and letting his own mind ease off the gas, Matt sat up. He shook his head to clear his thoughts and looked from Terry to Mr. Wayne. 

"H-how?"

Mr. Wayne huffed, "how? At which part?"

Good question, but Matt just wanted answers not sass. "Why is he Batman? He can't be Batman!"

"He's Batman because he believes it's what is right."

As little sense as that made, Matt didn't care. His brother couldn't be his hero! His brother was lame and bad in school and forgot to pick Matt up from class and never came to family day anymore and couldn't remember Mom's work schedule! He wasn't Batman! Batman was good and always helping people and had saved Matt's life before! It didn't add up.

"Okay, okay fine. Why did he... Why am I here? If it's such a secret, why would he expose himself like this?" Matt asked, sitting down on the caves floor.

"Don't rest now, help me move your brother to my table over there. I'll need to make sure he's DNA has returned to normal," the man gently knocked his cane against Matt's hip, nudging him up.

Matt reluctantly got up, helping Mr. Wayne carry Terry to a fancy looking exam table. The dog from before wiggled by, pushing Mr. Wayne aside to sniff at Matt. Matt tried to ignore him, a little intimidated by how big he was, and tried to remember his questions.

"So? Why am I here?"

Wayne hummed to himself a moment, getting to work on examining his brother, "I'm not Terry. I can't tell you why he brought you here exactly."

Matt groaned loudly in frustration, pushing the dog's nose away from where he was snuffling at Matt's face. "Well do you have a best guess?" 

The old man looked over at him with a grown, "I was getting to that. Ace, back away, boy." 

The overgrown dog took a few steps back, huffing in his own annoyance. He sat down next to Wayne, and Matt followed, plopping down into one of the empty seats near the table.

"If I had to make an estimated guess, I'd assume he was worried about you. He must have seen you and brought you back to where his muddled mind thought you could get help."

"Help? For what?" 

Mr. Wayne gave him a once over, "Matthew, you're bleeding from the forehead and you have a limp. After I fix your brother, I'll be checking on you."

Oh. Yea, Matt had forgotten about that.

"Oh. Yea, okay," Matt agreed, reaching up to inspect his head. The cut was no longer bleeding and the blood was mostly dry but there were wet patches here and there. Overall not so bad for being tossed through a broken window. 

"Stop playing with it," Mr. Wayne warned, "it may not be bad, but if it gets infected you'll be in a lot of pain."

Matt nodded, pulling his hand away, "so why here?"

Wayne gave him a grumpy look. Too bad, Matt thought, no way he was about to stop asking questions while he sat here wounded in the Batcave with his brother who happened to be  _ The Batman _ .

"Why would he take me here instead of the hospital? Or to our mom?" Matt rephrased.

"Perhaps to protect his identity from more people. Or because he knows instinctively I have patched him up in the past."

Matt let out a sigh, lounging back in his chair. This is a lot. He let his hand drop to the side and called over Ace, letting the dog sniff him some more and get some pets in. Mulling over all this information, Matt knew he and Terry we're gonna have more than a few arguments over this. Probably more one sided than anything, he was gonna yell at Terry for risking his life, and Terry would ignore him and Matt would lose Batman. 

Something about that scathed the most. He already didn't have Terry, and now Gotham's hero, his hero, was gone too. Cause that was also Terry, and Terry wasn't there for Matt so neither was Batman.

"Does he have to know?" 

Mr. Wayne looked back up at him. "Know what?" 

"That I know he's Batman?"

There was a quiet moment, only interrupted by the sounds of Ace getting pets. 

"By the time you're patched up, he'll more than likely be awake. And we can't be sure he wasn't conscious for all of this. He may already know you know." 

Matt retracted down further into his seat, pulling his hand away from Ace and ignoring the dogs whine.

"It's not fair."

"I'm sorry, Matthew. I'm sure Terry would have liked to tell you a different way." 

"No he wouldn't. He wasn't going to tell me. Ever. He doesn't tell me anything, fuck, he doesn't tell any of us anything. Cept maybe you," Matt huffed, forgoing all politeness.

"Language. Whether he planned to tell you or not, I'm sure he would have preferred it in another way. Your brother does care about you, Mathew," Mr. Wayne lectured.

Matt kicked his feet out. He felt too small, he wanted to throw a fit. Hit the table, kick at some of the expensive stuff lying around.

"Sure he does."

"He does. Very much so. He talks high praise about you and your mother."

"I'll believe that as soon as Terry starts coming home at a decent time. Or waking up to come with us on Family Day. Or when he remembers my soccer games," Matt ranted, twisting the hem of his shirt between his fingers.

Mr. Wayne didn't say anything else. Ace laid down back in his spot, and Matt sat quietly stewing over the past few hours. Like clockwork, after finishing work on Terry, Mr. Wayne waved him over and cleaned him up as well. 

Matt sat through it, following the motions and ignoring his brother laying next to him. When his turn was done and he had a bandage on his head and his ankle wrapped, he sat back down in his seat and waited.

Waited for Mr. Wayne to say something, waited for Terry to wake up, waited for whatever came next.

**Author's Note:**

> i guess i write now


End file.
